"Thermaltake's ISGC-100 is a low profile low noise heatsink for small and compact PC chassis. Three 6mm diameter copper heatpipes ensure good thermal conduction from the base to the fins of the 70mm tall heatsink. A 92mm PWM fan scales in speed from 600-1600RPM, directing airflow down through the horizontal aluminum fins of the heatsink. In real world terms the ISGC-100 heatsink ranges from moderately audible to completely silent."
FULL STORY @ FROSTYTECH (http://www.frostytech.com/articleview.cfm?articleID=2484)